T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
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volatile oil of t h e oleoresin has been identified in t h e wood turpentine of t h e three varieties of wood under examination. T h e physical properties a n d t h e percentage composition do not always agree, yet they coincide as closely as could be reasonably expected, when we consider t h e inaccuracies of some of t h e
SOME IMPROVED ELECTRICAL LABORATORY APPARATUS B y CHAS.MORRISJOHNSON Received July 23, 1915
I-QUICK
HEATING
ELECTRIC
FURSACE
FOR
THE
DE-
T E R M I N A T I O N OF C A R B O X I N S T E E L , E T C . , WITH TRAIX
T h e t r a i n (Fig. I) consists o f : ( I ) a mercury t u b e t o detect leaks a n d stoppages; ( 2 ) a safety jar containing a I : I solution of KOH; (3) a tower filled loosely with a plug of glass wool followed with anhydrous calcium chloride, a layer of soda lime a n d another
11
methods available. T h e results t h u s far obtained justify t h e conclusion t h a t t h e volatile oil obtained from distilling wood under diminished pressure is similar t o t h a t obtained from t h e oleoresin of t h e same species of tree. CHEMICAL LABORATORY, UNIVERSITY OF NSVADA RENO,NEVADA
LABORATORY AND PLANT
1
Vol. 7, No.
I
placeable heating element, a n d a supporting stand. The furnace will heat from t h e cold t o 1000' C. in 20 t o 2 j minutes with a current consumption of 3 t o 4 amperes. I t can be cooled rapidly, if desired, b y lifting off t h e t o p half of t h e split muffle. The writer has supplanted for some time in this laboratory, a n d in another laboratory under his direction, all of t h e type introduced b y him in 1908~with this new t y p e shown in Fig. I. This t y p e of electric furnace can be built in a n y length of heating surface with coils connected in parallel. T h e type shown in Fig. I is 1 3 inches long b y 35/32
FIG.I
plug of the wool; (4) a jar of short pieces of stick caustic potash with a plug of glass wool a t t h e t o p a n d a t t h e b o t t o m ; ( 5 ) a clay a n d rubber connector doing away with rubber stoppers a t t h e charging e n d ; (6) t h e vitrified clay combustion t u b e with t h e tapered outlet doing away with t h e rubber stopper at this point also; (8) is t h e jar of granulated zinc t o stop acid a n d sulfur; (9) is a jar of phosphoric acid powder a n d ( I O ) is t h e bulb for absorbing a n d weighing t h e C O S . This train was designed b y t h e writer, being a simplification of his train described in J . A m . Chem. SOC.,M a y , 1908. T h e writer has now used t h e tapered clay combustion tubes for over two years for t h e determination of carbon in steel, etc., a n d has been using t h e m for some months for oxygen determinations also. T h e new split muffle t y p e of furnace was designed a b o u t a year ago. I t is of most simple construction, consisting of a split muffle of kieselguhr, a coil of nichrome wire embedded in alundum cement as a re-
inches 0. D. a n d 1 1 ~ / I. ~ ~ D. The writer built t h e same type for organic work 18 inches long. By using three rheostats a long furnace can be made t o heat t o three different temperatures a t once or i t can be heated in one part if desired. T h e furnace presents a bright neat appearance with its white muffle; new heating elements can be kept in stock a n d quickly p u t in place in case of a burn-out as there are no screws or powdered heat insulation t o bother with. I n case t h e muffle becomes soiled i t can be p u t in a muffle furnace a n d heated t o a red heat for about 2 0 minutes when i t becomes.as white as new. The simple construction makes t h e furnace a very inexpensive one. By using a split insulation muffle of j 5 / s inches 0. D. a n d 2 5 / 3 2 I. D., t h e writer obtained a furnace of this t y p e which is developing 1020' C. with a current consumption of only 2 . 7 amperes. This furnace has been in daily service in this laboratory for several months. 1
J . Am. Chem. Sac., 80 (1908). 773.
Nov., r q r j
T I I E J O U R A T A I , OF I.VIIU:STKIAL A N D E Y G I N I I E R I N G C H B M I S T R Y
NSW TYPF. OF P O R T A B L E x.,iaonlxTom nn1:nsr:x.r Fig. I1 show-s the rheostat designed by t h e m i t e r with a yiew t o making repairs morc casy a n d to have a piece of apparatus with sufficient capacity t o fill the needs of most laboratories. It consists of 2 1 coils of nichrome wire giving a total resistance of 3o ohms a n d a maximum capacity of 14 amperes. I t can be
II--A
961
Tlic white casing makes a n attractive looking piece of apparatus. Thc int,erior mume on which the wire is wound is of a special composition which is now being tested out. This same composition used in comhustion boats made t h e remarkable run of j25 steel cornbustinns per boat with t h e test boats still in commission h u t considcrably worse for wear. It is highly
FIG. I1
Hi. 111
used either on t h e furnace shown in Fig. I or with the large one given in Fig. 111. I t holds t h e large furnace in Fig. 111. for a n y length of time at a n y temperature from zoo0 C. up t o Toon0 C. T h e rheostat occupies h u t a few inches of table width and can be set behind t h e other apparatus as illustrated in Fig. I. Repairs are casily made a n d the white board of hard asbestos board gives a cheerful effect. If desircd, twn such rhcostats can be bolted together making a double instrument. The rheos t a t is practically indestructible so long as it8 capacity is not exceeded as there i s nothing about its design to get out of repair. I n Fig. IT, X I is t h e front a n d 13 the back view showing details of construct.ion,
probahle t h a t the muMe will be cqually superior t o t h e old mixture for heating core mutfles. T h e scheme is t o keep these working'mumes already prepared with the heating wire cemented on them ready for usc so that repairs can be quickly made. As t h e furnace cnnsists of three parts its construction it is considerably cheaper t h a n t h a t of t h e old types, besides having the advantages already mentioned. T h e door opens horizontally: t h e author has found this arrangement to he much more desirable t h a n t h e vertically opening door used in some oi t h e old types.
III--- A K E W R E C T A X G U L A K L A B O R A T O R Y EI.ECTR1C
A NEW DIRECT-READING VISCOSIMETER B~ n. F. X~ACMICHIY,.
4Il:FFT.I'
P C R K A C E WIT11 SOl.ID 1IEXT
I,RBOXAT"IY
O B Tllll P A K K W O K l i S
C R I J C ~ B L ESTIITL COITPAPIY OP AWSRICA E'ITIS."XCII
IXSlILATlOh' CASE
m c r i v c a scpiciilhcr 8 . 1 9 1 s
The furnace shown in Pig. I11 is in principle just the samc 3s t h c cylindrical furnace described in Fig. I . A white solid case of kicselguhr surrounds the heating element and working muffle which has a n nvailahlc working space of r i 1 / 2 X j X j in. This is ampic ior most laboratories. To control t h e temperature of t h e furnace t h e rheostat shown in Fig. I1 is used a n d b y means of it any dcsircd temperature can be maintained for hours at a time tip t o ioooo C. T h e author keeps thrce furnaces af this size i n constant servicc. On a c c o u n t of tho simplicity of construction, t h e repairs can h e casily madc and, as no insulating powder is used, t h e furnace is irce from pow
